Sanding block



N. E. MOYER SANDING BLOCK March 16, 1965 2 Sheets-Sheet 1 Filed Sept. 4,1962 INVENTOR. 06541.) E. IMO/ER ATTOR/YEKF N. E. MOYER SANDING BLOCKMarch 1 1965 2 Sheets-Sheet 2 Filed Sept. 4, 1962 INVENTOR. WEAL) 5.MOYE/P ATTOPIYEYS United States Patent 3,173,231 SANDING BLOCK N ealy E.Meyer, Rte. 2, Blue Springs, Me. Filed Sept. 4, 1962, Ser. No. 221,000 4Claims. (Cl. 51-391) This invention relates to abrading tools, and moreparticularly to improvements in hand-held sanding blocks.

In many applications, and particularly with regard to the repair ofmodern automobile bodies, elongated concave grooves must be abraded forremoving unwanted filling material and smoothing prior to finishing.Such grooves are formed on many difierent radii and heretofore a greatnumber of different sanding tools were required in order to permit theselection of one which presented a matching convex surface for accurateforming. Various attempts have been made to avoid the bother and expenseof stocking a great number of abrading tools by using resilient cores orresilient material layers beneath abrading sheet material for bulgingsame into the desired curvature. Such attempts have generally not beensatisfactory because variations in pressure against the abrading toolproduced variations in the curvature of the cutting surface, renderingit very difiicult to produce an accurate smooth groove suitable forfinishing. Attempts have also been made to produce rigid core abradingtools having curved surfaces over which abrasive sheets may bestretched; however, such devices often presented difi'iculties in sheetmounting and failed to maintain the abrasive sheet in a sufiicientlytightly stretched condition over a length required for accurate work.

The principal objects of the present invention are: to provide anabrading device which presents an elongated rigid cutting surface havinga transverse cross-sectional contour of constantly changing convexcurvature for ease in fitting into elongated concave grooves of variousradii; to provide the combination of an elongated abrasive sleeve and asleeve supporting core which cooperate with each other in producing anelongated rigid abrading tool; to provide a simple abrading devicewherein a sleeve having abrasive material on the outside surface thereofacts to prevent axial bending between segmented portions of a core whichforms and supports the sleeve in a desired peripheral contour; toprovide such a device wherein the core is snugly slidably received inthe sleeve and, without further adjustment being required, transverselydeforms the sleeve into a shape conforming to the outside surface of thecore; to provide such a device which may be used in lengthened orshortened form depending upon the tool length desired; and to providesuch a combination wherein adjustable parts for clamping or unclampingthe abrasive material are not required.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings wherein are set forth by way of illustration and examplecertain embodiments of this invention.

FIG. 1 is a perspective view of an assembled abrading tool embodyingthis invention with a part broken away to show connected core portions.

FIG. 2 is a fragmentary perspective view on a reduced scale showing theuse of the abrading tool of FIG. 1 on an automobile body groove.

FIG. 3 is a fragmentary cross-sectional view through the tool andautomobile body of FIG. 2 showing a portion of the abrading surface incurving contact with the automobile body groove.

FIG. 4 is an exploded view showing two elongated axially separablesegmented portions of an abrasive sleeve supporting core embodying thisinvention.

FIG. 5 is a perspective view showing an elongated abrasive sleeve incommercially available cylindrical form.

FIG. 6 is a fragmentary cross-sectional view on an enlarged scale takenlongitudinally through one end of the core particularly illustrating afinger receiving grasping socket for withdrawing a core portion from theabrasive sleeve.

FIG. 7 is a fragmentary perspective view illustrating aligning andjoining members on the core portions.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates an abrading tool or sandingblock embodying this invention. The tool 1 includes an elongatedabrasive sleeve 2 and a sleeve supporting core 3. The sleeve 2, prior toassembly with the core 3, is normally in the form of an elongatedcylinder (FIG. 5) which is commercially available in many desiredlengths and grits and, if desired, may be easily cut to shorter lengths.The sleeve 2 is substantially smooth on the inside surface 4 thereof. Inthe illustrated example said inside surface 4 is composed of a biasedcut fabric impregnated or coated with a suitable synthetic resin so thatit will firmly adhere to a paper cylinder 5 which carries an abrasivematerial or grit 6 on the outside surface 7 thereof. The sleeve 2 is ofthe common type which is relatively easily deformable in transversecross-sectional profile but strong or substantially rigid against axialbendmg.

The core 3, in the illustrated example, is composed of two elongatedstraight rigid axially separable segmented portions respectivelydesignated 8 and 9, which are preferably of different lengths for apurpose described hereinafter. A greater number of core portions may beused without departing from the spirit of this invention. The portion 9has a suitable square-shaped depression 10 in the end thereof facing theportion 3 and the portion 8 has a square-shaped projection 11 adapted tobe received in the depression 10 for aligning and axially joining theportions 8 and 9 together. It is to be understood that the clearancesbetween the depression 10 and projection 11 are such that the portions 8and 9 are generally main tained in a coaxial relationship; however, ifsmall transverse forces are applied, the portions 8 and 9 will separateslightly forming an angle with each other at the plane 12 of juncture.

The core 3 (when the portions 8 and 0 are joined to gether) has a lengthsubstantially equal to the length of the sleeve 2. The core 3 is formedof any suitable material such as aluminum or wood and has a constanttransverse cross-sectional peripheral contour 13 along the entire lengththereof. The peripheral contour 13 of the core 3 has a continuousconstantly changing convex curvature terminating at outwardly oppositelyfacing ends 14 and 15 thereof in apices of respectively differentcurvatures. The constantly changing convex curvatures as they extendaway from the ends 14 and 15 are believed to be best characterized assections of parabolas. The peripheral contour 13 of the core 3 has acircumference substantially equal to or slightly less than thecircumference of the sleeve inside surface 4 whereby the core 3 may besnugly slidably received in the sleeve 2. It has been found that .040 or.050 inch diiference on a three inch circumference permits adequatesliding therebetween. When inserted in the sleeve, the core 2transversely deforms the sleeve whereupon the abrasive surface 7conforms to the core peripheral contour 13.

Since the sleeve 2 is substantially rigid in axial bendingcharacteristics, the combination of sleeve and core presents a devicewhich is axially rigid, although the portions 8 and 9 of the corewithout the sleeve would admit to axial bending with respect to eachother. Thus the sleeve and core form an elongated abrading toolpresenting a rigid advantageously curved abrading surface.

In operation, the abrading tool 1 is held in the hands and urged againstthe automobile body 16. The tool 1 is rotated along the longitudinalaxis thereof until the proper curvature is received in and contacts thedesired concave area 17 of the body'groove 17'. As much pressure asdesired may then be placed on the tool 1 in the direction of the groovecenter, and the tool is reciprocated longitudinally of the groove untilproper smoothing and blending is obtained. The application or release ofpressure against the tool 1 will not result in a changing of theabrading surface curvature since there is rigid support therebeneath.Since the length of the sleeve 2 and core 3 are substantially equal,nothing extends outwardly of the ends of the tool 1 to interfere withthe operation thereof in places having limited working space.

It is desirable to have grasping means to facilitate removing the corefrom the sleeve, for example, to exchange the sleeve for one ofdifferent grit. In the illustrated example, such grasping meanscomprises a sloping depression or passageway 18 entering into the bodyof the core 3 at the outside ends 19. The passageway 18 is of sufficientsize to permit the entry of a finger 20 thereinto and a suitable crosspin 21 extends through the body of the sleeve 2 permitting the finger 20to engage therewith in applying an axial withdrawal force on the core 3with respect to the sleeve 2. It is noted that the cooperating guidingmember (depression and projection 11) easily separate axially of thetool 1 and the respective portions 8 and 9 may be withdrawn fromopposite ends of the sleeve 2 with much greater ease than a singleelongated core since friction between the sleeve and core acting againstwithdrawal operates only on the shorter individual core portions.

It has been found that a convenient length for the tool 1 is 20 incheswith the individual core portions 8 and 9 being 6 inches and 14 inchesin length respectively. If a short length abrading tool is desired,either of the portions 8 or 9 may be used individually by severing alength of the sleeve 2 to the proper dimension.

The above-described abrading tool is highly convenient for not onlyremoving filler to the proper depth and contour for painting within agroove, but the groove curves may be blended into other surfaces easilyand without the great skill heretofore necessary for such operation. Itis to be understood that although one form of this invention has beenillustrated and described, it is not to be limited to the specific formor arrangement of parts herein 7 described and shown except insofar assuch limitations are included in the claims.

What I claim and desire to secure by Letters Patent is: 1. Incombination, an elongated abrasive sleeve and an elongated and sleevesupporting core:

said core being of rigid material and unitary in crosssection transverseto the length thereof and of constant transverse cross-sectionalperipheral contour along the length thereof,

(c) said core peripheral contour having a circumference substantiallyequal to the circumference of said sleeve inside surface, said coreperipheral contour having a continuous constantly changing convexcurvature terminating at outwardly oppositely facing ends thereof inapices of respectively different curvature,

(:1) said core being snugly slidably received in said sleeve andtransversely deforming said sleeve whereupon said outside surfacethereof conforms to said core peripheral contour, whereby an elongatedrigid concave groove abrading tool is formed.

2. The combination of claim 1 including:

(a) finger-engaging means on end of said core for slidably removing saidcore from said sleeve.

3. In combination, an elongated abrasive sleeve and an elongated sleevesupporting core:

(a) said sleeve normally being cylindrical in form and substantiallysmooth on the inside surface thereof and having abrasive material on theoutside surface thereof, said sleeve being easily deformable intransverse cross-sectional profile but substantially rigid in axialbending,

(b) said supporting core being composed of at least two elongatedstraight segmented portions axially separable along the longitudinalaxis of said core, cooperating guide means on said portions for axiallyjoining same but permitting axial bending therebetween, said core havinga length substantially equal to the length of said sleeve, said corebeing of rigid material and unitary in cross-section transverse to saidaxis and of constant transverse cross-sectional peripheral contour alongthe length thereof,

(0) said core peripheral contour having a continuous constantly changingconvex curvature and having a circumference substantially equal to thecircumference of said sleeve inside surface,

(0.) said core being snugly slidably received in said sleeve andtransversely deforming said sleeve whereupon said outside surfacethereof conforms to said core peripheral contour,

(2) said sleeve maintaining said core portions in coaxial relationwhereby an elongated rigid concave groove abrading tool is formed.

4. The combination of claim 3 including:

(a) finger-engaging means on outer ends of said core for slidablyremoving said portions from said sleeve.

References Cited by the Examiner UNITED STATES PATENTS 3/42 Johnson51-185 1/50 Bonkowski 51-187 11/50 Stucker 51l87 @WW. have

1. IN COMBINATION, AN ELONGATED ABRASIVE SLEEVE AND AN ELONGATED ANDSLEEVE SUPPORTING CORE: (A) SAID SLEEVE NORMALLY BEING CYLINDRICAL INFORM AND SUBSTANTIALLY SMOOTH ON THE INSIDE SURFACE THEREOF AND HAVINGABRASIVE MATERIAL ON THE OUTSIDE SURFACE THEREOF, SAID SLEEVE BEINGEASILY DEFORMABLE IN TRANSVERSE CROSS-SECTIONAL PROFILE BUTSUBSTANTIALLY RIGID IN AXIAL BENDING. (B) SAID SUPPORTING CORE BEINGSTRAIGHT AND HAVING A LENGTH SUBSTANTIALLY EQUAL TO THE LENGTH OF SAIDSLEEVE, SAID CORE BEING OF RIGID MATERIAL AND UNITARY IN CROSSSECTIONTRANSVERSE TO THE LENGTH THEREOF AND OF CONSTANT TRANSVERSECROSS-SECTIONAL PERIPHERAL CONTOUR ALONG THE LENGTH THEREOF, (C) SAIDCORE PERIPHERAL CONTOUR HAVING A CIRCUMFERENCE SUBSTANTIALLY EQUAL TOTHE CIRCUMFERENCE OF SAID SLEEVE